U.S. patent application number 15/767576 was filed with the patent office on 2018-10-04 for soft magnetic alloy.
The applicant listed for this patent is LG INNOTEK CO., LTD.. Invention is credited to Seok BAE, Jong Soo HAN, Hyo Yun JUNG, So Yeon KIM, Sang Won LEE, Jai Hoon YEOM.
Application Number | 20180286547 15/767576 |
Document ID | / |
Family ID | 58557670 |
Filed Date | 2018-10-04 |
United States Patent
Application |
20180286547 |
Kind Code |
A1 |
KIM; So Yeon ; et
al. |
October 4, 2018 |
SOFT MAGNETIC ALLOY
Abstract
A soft magnetic alloy according to an embodiment of the present
invention has a composition of Formula below:
Fe.sub.aX.sub.bY.sub.cZ.sub.d [Formula] wherein, in the above
Formula, X includes at least one of silicon (Si) and phosphorus
(P), Y includes carbon (C), Z includes at least one of boron (B),
nitrogen (N), aluminum (Al), titanium (Ti), zirconium (Zr), hafnium
(Hf), niobium (Nb), tantalum (Ta), chromium (Cr), molybdenum (Mo),
cobalt (Co), and nickel (Ni), a ranges from 78 at % to 95.75 at %,
b ranges from 2 at % to 16 at %, c ranges from 2 at % to 8 at %,
and d ranges from 0.25 at % to 10 at %.
Inventors: |
KIM; So Yeon; (Seoul,
KR) ; BAE; Seok; (Seoul, KR) ; YEOM; Jai
Hoon; (Seoul, KR) ; LEE; Sang Won; (Seoul,
KR) ; HAN; Jong Soo; (Seoul, KR) ; JUNG; Hyo
Yun; (Seoul, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
LG INNOTEK CO., LTD. |
Seoul |
|
KR |
|
|
Family ID: |
58557670 |
Appl. No.: |
15/767576 |
Filed: |
October 14, 2016 |
PCT Filed: |
October 14, 2016 |
PCT NO: |
PCT/KR2016/011564 |
371 Date: |
April 11, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01F 38/14 20130101;
C22C 2202/02 20130101; H01F 3/04 20130101; H01F 41/0226 20130101;
C22C 33/04 20130101; C22C 38/00 20130101; C22C 38/002 20130101;
C22C 45/02 20130101; H01F 27/36 20130101; H01F 1/15308 20130101;
H01F 1/15341 20130101; C22C 2200/04 20130101; C22C 38/10 20130101;
H01F 1/14775 20130101; C22C 38/02 20130101; C22C 38/06 20130101;
C22C 2200/02 20130101; H01F 1/15333 20130101; C22C 33/003 20130101;
H01Q 1/526 20130101 |
International
Class: |
H01F 1/153 20060101
H01F001/153; H01F 1/147 20060101 H01F001/147; H01Q 1/52 20060101
H01Q001/52; C22C 45/02 20060101 C22C045/02; C22C 38/02 20060101
C22C038/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2015 |
KR |
10-2015-0146232 |
Claims
1. A soft magnetic core comprising: a nanocrystalline ribbon or an
amorphous ribbon, wherein the nanocrystalline ribbon or the
amorphous ribbon is wound, wherein the nanocrystalline ribbon or
the amorphous ribbon consists of a soft magnetic alloy having a
composition of Formula below: Fe.sub.aX.sub.bY.sub.cZ.sub.d
[Formula] wherein, in the above Formula, X comprises at least one
of silicon (Si) and phosphorus (P), Y comprises carbon (C), Z
comprises at least one of boron (B), nitrogen (N), aluminum (Al),
titanium (Ti), zirconium (Zr), hafnium (Hf), niobium (Nb), tantalum
(Ta), chromium (Cr), molybdenum (Mo), cobalt (Co), and nickel (Ni),
a ranges from 78 at % to 95.75 at %, b ranges from 2 at % to 16 at
%, c ranges from 2 at % to 8 at %, and d ranges from 0.25 at % to
10 at %.
2. The soft magnetic core of claim 1, wherein each of the Si and
the P is included so as not to exceed 8 at %.
3. The soft magnetic core of claim 2, wherein the b ranges from 4
at % to 12 at %, c ranges from 4 at % to 8 at %, and d ranges from
2 at % to 8 at %.
4. The soft magnetic core of claim 1, wherein the Z comprises
B.
5. The soft magnetic core of claim 4, wherein the Z further
comprises Al.
6. The soft magnetic core of claim 4, wherein the Z further
comprises Co.
7. The soft magnetic core of claim 4, wherein the Z further
comprises Cr.
8. The soft magnetic core of claim 1, wherein the soft magnetic
alloy has a saturation magnetic flux density of 170 emu/g or
more.
9. The soft magnetic core of claim 1, wherein the soft magnetic
core is applied to at least one of a transformer, a motor, an
inductor or a wireless power transmitter.
10. A shielding sheet for an antenna, the shielding sheet
comprising a plurality of nanocrystalline ribbons which are stacked
or a plurality of amorphous ribbons which are stacked, wherein the
plurality of nanocrystalline ribbons or the plurality of amorphous
ribbons consist of a soft magnetic alloy having a composition of
Formula below: Fe.sub.aX.sub.bY.sub.cZ.sub.d [Formula] wherein, in
the above Formula, X comprises at least one of silicon (Si) and
phosphorus (P), Y comprises carbon (C), Z comprises at least one of
boron (B), nitrogen (N), aluminum (Al), titanium (Ti), zirconium
(Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), chromium (Cr),
molybdenum (Mo), cobalt (Co), and nickel (Ni), a ranges from 78 at
% to 95.75 at %, b ranges from 2 at % to 16 at %, c ranges from 2
at % to 8 at %, and d ranges from 0.25 at % to 10 at %.
11.-15. (canceled)
16. A method of forming a soft magnetic core, the method
comprising: preparing a molten solution by mixing and melting
powder having a composition of Formula below; producing a
nanocrystalline ribbon or an amorphous ribbon by cooling the molten
solution; heat-treating the nanocrystalline ribbon or the amorphous
ribbon; and forming a soft magnetic core by winding the
heat-treated nanocrystalline ribbon or the heat-treated amorphous
ribbon: Fe.sub.aX.sub.bY.sub.cZ.sub.d [Formula] wherein, in the
above Formula, X comprises at least one of silicon (Si) and
phosphorus (P), Y comprises carbon (C), Z comprises at least one of
boron (B), nitrogen (N), aluminum (Al), titanium (Ti), zirconium
(Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), chromium (Cr),
molybdenum (Mo), cobalt (Co), and nickel (Ni), a ranges from 78 at
% to 95.75 at %, b ranges from 2 at % to 16 at %, c ranges from 2
at % to 8 at %, and d ranges from 0.25 at % to 10 at %.
17. The method of claim 16, wherein the molten solution is cooled
by spraying a gas comprising at least one of N.sub.2 and Ar, or
water.
18. The shielding sheet for the antenna of claim 10, wherein each
of the Si and the P is included so as not to exceed 8 at %.
19. The shielding sheet for the antenna of claim 18, wherein the b
ranges from 4 at % to 12 at %, c ranges from 4 at % to 8 at %, and
d ranges from 2 at % to 8 at %.
20. The shielding sheet for the antenna of claim 10, wherein the
shielding sheet is applied to a wireless power receiver.
Description
TECHNICAL FIELD
[0001] The present invention relates to a soft magnetic alloy, and
more particularly, to an amorphous or nanocrystalline soft magnetic
alloy.
BACKGROUND ART
[0002] Recently, there is a growing demand for the use of high
performance soft magnetic materials in a variety of electronic
devices such as computers, machines, and communication devices.
Thus, to realize physical properties that cannot be provided by
existing materials such as silicon steel and ferrite, the use of
high-performance soft magnetic metal materials is highly required.
Soft magnetic metal materials having high saturation magnetic flux
density, high magnetic permeability, and resistivity
characteristics may be used for general purposes, and it is
possible to realize characteristics such as small sizes, light
weights, and low loss by replacing existing components.
Specifically, high performance soft magnetic materials may be
applied to soft magnetic cores such as inductors, choke coils, and
transformers, and various sheets for shielding electromagnetic
fields.
[0003] Up to now, Fe-based amorphous alloys have mainly been used
to meet the requirement for high saturation flux density
characteristics. Among them, when higher saturation flux density
and superior amorphous characteristics are required, Fe--Si--B
ternary soft magnetic alloys are applied. For this, in addition to
Fe, a metalloid element and an additional metal element should be
contained in a predetermined amount or more. However, as the
metalloid element and the additional metal element are included in
larger amounts, Fe should be included in a relatively smaller
amount, and thus saturation magnetic flux density tends to be 165
emu/g or less. Therefore, such a Fe--Si--B soft magnetic alloy has
a limitation in being applied to environmentally friendly
automobiles and high-performance electronic devices which require
high saturation magnetic flux density.
DISCLOSURE
Technical Problem
[0004] An object of the present invention is to provide an
amorphous or nanocrystalline soft magnetic alloy having high
saturation magnetic flux density.
Technical Solution
[0005] A soft magnetic alloy according to an embodiment of the
present invention has a composition of Formula below:
Fe.sub.aX.sub.bY.sub.cZ.sub.d [Formula]
wherein, in the above Formula, X includes at least one of silicon
(Si) and phosphorus (P), Y includes carbon (C), Z includes at least
one of boron (B), nitrogen (N), aluminum (Al), titanium (Ti),
zirconium (Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), chromium
(Cr), molybdenum (Mo), cobalt (Co), and nickel (Ni), a ranges from
78 at % to 95.75 at %, b ranges from 2 at % to 16 at %, c ranges
from 2 at % to 8 at %, and d ranges from 0.25 at % to 10 at %.
[0006] The Si may be included in an amount of 2 at % to 8 at %.
[0007] The P may be included in an amount of 2 at % to 8 at %.
[0008] The Z may include B.
[0009] The Z may further include Al.
[0010] The Z may further include Co.
[0011] The Z may further include Cr.
[0012] The soft magnetic alloy according to an embodiment of the
present invention may have a saturation magnetic flux density of
170 emu/g or more.
[0013] The soft magnetic alloy according to an embodiment of the
present invention may be amorphous or nanocrystalline.
[0014] A method of forming a soft magnetic core, according to an
embodiment of the present invention, includes: preparing a molten
solution by mixing and melting powder having a composition of
Formula below; forming a ribbon by cooling the molten solution;
heat-treating the ribbon; and forming a soft magnetic core by
winding the heat-treated ribbon.
Fe.sub.aX.sub.bY.sub.cZ.sub.d [Formula]
wherein, in the above Formula, X includes at least one of silicon
(Si) and phosphorus (P), Y includes carbon (C), Z includes at least
one of boron (B), nitrogen (N), aluminum (Al), titanium (Ti),
zirconium (Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), chromium
(Cr), molybdenum (Mo), cobalt (Co), and nickel (Ni), a ranges from
78 at % to 95.75 at %, b ranges from 2 at % to 16 at %, c ranges
from 2 at % to 8 at %, and d ranges from 0.25 at % to 10 at %.
[0015] The molten solution may be cooled by spraying a gas
including at least one of N.sub.2 and Ar, or water.
Advantageous Effects
[0016] According to an embodiment of the present invention, a soft
magnetic alloy having excellent amorphous or nanocrystalline
formability and a saturation magnetic flux density of 170 emu/g or
more can be obtained. The soft magnetic alloy according to an
embodiment of the present invention can be applied to wireless
power transmitters/receivers for wireless charging, RFID tags,
various shielding sheets, transformers, inductors, choke coils, and
the like.
DESCRIPTION OF DRAWINGS
[0017] FIG. 1 illustrates a transformer including a soft magnetic
core according to an embodiment of the present invention.
[0018] FIG. 2 illustrates a soft magnetic core formed by winding an
amorphous or nanocrystalline ribbon made of a soft magnetic alloy
according to an embodiment of the present invention.
[0019] FIG. 3 is a partial view of a wireless power transmitter
according to an embodiment of the present invention.
[0020] FIG. 4 is a partial view of a wireless power receiver
according to an embodiment of the present invention.
[0021] FIG. 5 is a flowchart illustrating a method of preparing a
soft magnetic alloy, according to an embodiment of the present
invention.
[0022] FIG. 6 is a thermal analysis graph of a soft magnetic alloy
prepared according to Example 1.
[0023] FIG. 7 illustrates X-ray diffraction (XRD) pattern analysis
of the soft magnetic alloy of Example 1.
[0024] FIG. 8 illustrates the saturation magnetic flux density of
Example 1.
MODE OF THE INVENTION
[0025] As the present invention allows for various changes and
numerous embodiments, particular embodiments will be illustrated in
the drawings and described in detail. However, this is not intended
to limit the present invention to particular modes of practice, and
it is to be appreciated that all changes, equivalents, and
substitutes that do not depart from the spirit and technical scope
of the present invention are encompassed in the present
invention.
[0026] Although terms including ordinal numbers, such as "first,"
"second," and the like, may be used to describe various components,
such components must not be limited by the above terms. The above
terms are used only to distinguish one component from another. For
example, a first element can be named a second element, and
similarly, the second element can be named the first element
without departing from the scope of the present invention. The term
"and/or" includes any and all combinations of one or more of the
associated listed items.
[0027] When it is described that a certain element is "connected"
or "linked" to another element, it should be understood that the
certain element may be connected or linked to the other element
directly or via another element present therebetween. In contrast,
when a certain element is "directly connected" or "directly linked"
to another element, it should be understood that there are no other
elements present therebetween.
[0028] The terminology used in the application is used only to
describe specific embodiments and is not intended to limit the
present invention. An expression in the singular includes an
expression in the plural unless the content clearly indicates
otherwise. In the application, it should be understood that terms,
such as "include" and "have", are used to indicate the presence of
stated features, numbers, steps, operations, elements, parts, or a
combination thereof without excluding in advance the possibility of
the presence or addition of one or more other features, numbers,
steps, operations, elements, parts, or combinations thereof.
[0029] All terms used herein including technical or scientific
terms have the same meaning as those generally understood by those
of ordinary skill in the art unless otherwise defined. It should be
understood that terms generally used, which are defined in a
dictionary, have the same meaning as in the context of the related
art, and the terms are not interpreted with an ideal or excessively
formal meaning unless otherwise clearly defined in the
application.
[0030] Hereinafter, embodiments will be described in detail with
reference to the accompanying drawings, wherein the like or
corresponding elements denote the like reference numerals, and
redundant description thereof will be omitted.
[0031] A soft magnetic alloy according to an embodiment of the
present invention may be applied to soft magnetic cores such as
inductors, choke coils, transformers, and the like, and various
sheets for shielding electromagnetic fields. For example, the soft
magnetic alloy according to an embodiment of the present invention
may also be applied to a soft magnetic core for a transformer, a
soft magnetic core for a motor, or a magnetic core for an inductor.
The soft magnetic alloy according to an embodiment of the present
invention may be applied to a magnetic core in which a coil is
wound or a magnetic core in which a wound coil is accommodated.
When amorphous or nanocrystalline powder having high saturation
magnetic flux density is used as a magnetic core of a transformer,
an inductor, or the like, the magnetic core may be more lightweight
than existing materials, and characteristics such as a low energy
loss, i.e., high energy efficiency, due to excellent resistivity
characteristics may be achieved. Accordingly, a magnetic core in an
electronic device may be small-sized and lightweight and have high
efficiency. Meanwhile, when amorphous or nanocrystalline powder is
used as a magnetic sheet for shielding, the magnetic sheet has a
smaller thickness and an increased shielding efficiency, and thus
it is easy to achieve a light weight and high efficiency of a
wireless charging device.
[0032] FIG. 1 illustrates a transformer 100 including a soft
magnetic core according to an embodiment of the present
invention.
[0033] Referring to FIG. 1, the transformer 100, which is
configured to change an alternating voltage by electromagnetic
induction, includes a soft magnetic core 110 and coils 120 wound on
opposite sides of the soft magnetic core 110. Since a change in the
magnetic field that is generated when an alternating current is
input to a primary coil affects a secondary coil through the soft
magnetic core 110, magnetic flux of the secondary coil is changed
and, accordingly, a current is induced in the secondary coil. In
this regard, the soft magnetic core 110 may be molded using the
soft magnetic alloy according to an embodiment of the present
invention, or may be formed by winding an amorphous or
nanocrystalline ribbon made of the soft magnetic alloy according to
an embodiment of the present invention.
[0034] FIG. 2 illustrates a soft magnetic core 200 made of the soft
magnetic alloy according to an embodiment of the present
invention.
[0035] Referring to FIG. 2, the soft magnetic core 200 may be
formed by winding an amorphous or nanocrystalline ribbon 210 made
of the soft magnetic alloy according to an embodiment of the
present invention. The soft magnetic core 200 may be applied to a
transformer, a motor, an inductor, and the like.
[0036] FIG. 3 is a partial view of a wireless power transmitter
1200 according to an embodiment of the present invention. FIG. 4 is
a partial view of a wireless power receiver 1300 according to an
embodiment of the present invention.
[0037] Referring to FIG. 3, the wireless power transmitter 1200
includes a soft magnetic core 1210 and a permanent magnet 1220.
[0038] The soft magnetic core 1210 may consist of a soft magnetic
material having a thickness of several millimeters. The soft
magnetic core 1210 may be molded using the soft magnetic alloy
according to an embodiment of the present invention, or may be
formed by winding an amorphous or nanocrystalline ribbon made of
the soft magnetic alloy according to an embodiment of the present
invention. In addition, the transmitter coil 1220 may be disposed
on the soft magnetic core 1210. Although not shown in the drawing,
a permanent magnet may be further disposed on the soft magnetic
core 1210, and the permanent magnet may be surrounded by the
transmitter coil 1220.
[0039] Referring to FIG. 4, the wireless powder receiver 1300
includes a soft magnetic substrate 1310 and a receiver coil 1320,
and the receiver coil 1320 may be disposed on the soft magnetic
substrate 1310.
[0040] The receiver coil 1320 may consist of coil surfaces, on the
soft magnetic substrate 1310, wound in parallel to the soft
magnetic substrate 1310. The soft magnetic substrate 1310 may be
molded using the soft magnetic alloy according to an embodiment of
the present invention, or may be formed by winding an amorphous or
nanocrystalline ribbon made of the soft magnetic alloy according to
an embodiment of the present invention.
[0041] Although not shown in the drawing, when the wireless power
receiver 1300 has both a wireless charging function and a near
field communication (NFC) function, an NFC coil may further be
mounted on the soft magnetic substrate 1310. The NFC coil may be
formed so as to surround an outer side of the receiver coil
1320.
[0042] According to one embodiment of the present invention, a soft
magnetic core of a transformer, a motor, and an inductor, a soft
magnetic core of a wireless power transmitter, a soft magnetic
substrate of a wireless power receiver, and the like include a soft
magnetic alloy having a composition of Formula 1 below:
Fe.sub.aX.sub.bY.sub.cZ.sub.d [Formula 1]
wherein, in Formula 1, X includes at least one of silicon (Si) and
phosphorus (P), Y includes carbon (C), Z includes at least one
element of boron (B), nitrogen (N), aluminum (Al), titanium (Ti),
zirconium (Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), chromium
(Cr), molybdenum (Mo), cobalt (Co), and nickel (Ni), a ranges from
78 at % to 95.75 at %, b ranges from 2 at % to 16 at %, preferably
4 at % to 12 at %, and more preferably 8 at % to 10 at %, c ranges
from 2 at % to 8 at %, preferably 4 at % to 8 at %, and d ranges
from 0.25 at % to 10 at %, preferably 2 at % to 8 at %, and more
preferably 4 at % to 8 at %.
[0043] Accordingly, a soft magnetic alloy having a saturation
magnetic flux density of 170 emu/g or more and excellent amorphous
or nanocrystalline formability may be obtained.
[0044] Here, the soft magnetic alloy according to an embodiment of
the present invention may include at least one of Si and P. When
the soft magnetic alloy according to an embodiment of the present
invention includes both Si and P, Si and P may be included in an
amount of 2 at % to 16 at %. When the amounts of Si and P are less
than 2 at %, resistivity may be lowered and amorphous formability
may be deteriorated. On the other hand, when the amounts of Si and
P are greater than 16 at %, the content of Fe is relatively low,
and thus saturation magnetic flux density may be reduced. When the
soft magnetic alloy according to an embodiment of the present
invention includes Si or P, the content of Si or P may range from 2
at % to 8 at %. When the content of Si or P is greater than 8 at %,
the possibility of intermetallic compound formation may increase
and saturation magnetic flux density may be lowered.
[0045] Among components of the soft magnetic alloy according to an
embodiment of the present invention, C has strong atomic affinity
with Fe. That is, C has a strong interatomic attraction with Fe,
i.e., about two times that of B. Accordingly, when Fe and C are
melted together, clustering and nucleation occur very easily in a
super-cooled molten solution, and amorphous formability may be
enhanced. Thus, when C is included in an amount of less than 2 at
%, an amorphous formability enhancement effect may be low, and when
C is included in an amount exceeding 8 at %, the possibility of
intermetallic compound formation may increase and saturation
magnetic flux density may be reduced.
[0046] Meanwhile, the soft magnetic alloy according to an
embodiment of the present invention may further include, in
addition to Fe, Si, P, and C, an additional element that acts as
one of a metalloid-based element, a growth inhibitor, and a
nucleation agent. The additional element includes, for example, at
least one of B, N, Al, Ti, Zr, Hf, Nb, Ta, Cr, Mo, Co, and Ni.
[0047] Here, B may serve to enhance amorphous or nanocrystalline
formability. That is, when Fe, Si, B, and C are melted in a molten
metal and then cooled, the interatomic bonding force between Fe and
C is higher than that between Fe and B, and thus C hinders
crystallization between Fe and B. Accordingly, crystallization
kinetics competition occurs due to a difference in interatomic
bonding force between Fe--B and Fe--C, and thus high amorphous
formability may be induced.
[0048] In addition, Cr acts as a growth inhibitor, enhances
electrical resistance, and increases corrosion resistance by
forming an oxide film on the soft magnetic alloy. For example, Cr
may prevent corrosion that may occur in a process of preparing or
drying a Fe-containing soft magnetic alloy.
[0049] However, when the additional element is included in an
amount exceeding 10 at %, an additional compound may be produced,
or raw material costs may be increased, and the content of Fe is
relatively low, resulting in reduced saturation magnetic flux
density.
[0050] FIG. 5 is a flowchart illustrating a method of preparing a
soft magnetic core, according to an embodiment of the present
invention.
[0051] Referring to FIG. 5, raw material powder having the
composition of Formula 1 is mixed in a molten metal, and melted at
1,500.degree. C. to 1,900.degree. C. (S500).
[0052] Subsequently, the resulting molten solution was rapidly
cooled to thereby produce alloy powder or a ribbon (S510). To
produce alloy powder, a gas including at least one of N.sub.2 and
Ar, or water may be sprayed onto the molten solution. In addition,
to produce a ribbon, the molten solution may be put into a mold and
rapidly cooled. Here, the ribbon may be an amorphous or
nanocrystalline ribbon.
[0053] Next, the alloy powder or the ribbon is heat-treated at a
temperature of 200.degree. C. to 1,000.degree. C. for 5 minutes to
24 hours (S520). The heat treatment process may be performed in a
gas atmosphere including at least one of H.sub.2, N.sub.2, Ar, and
NH.sub.3 under the presence or absence of a magnetic field. At this
time, when the heat treatment time is less than 5 minutes, an
effect of enhancing soft magnetic characteristics by heat treatment
may be deteriorated. In addition, when the heat treatment
temperature is less than 200.degree. C., the heat treatment time is
increased, and thus economic efficiency is lowered, and when the
heat treatment temperature is greater than 1,000.degree. C., the
alloy powder or the ribbon may be melted again.
[0054] Next, the heat-treated ribbon is wound, or the heat-treated
alloy powder is molded, to form a soft magnetic core (S530).
[0055] Hereinafter, the present disclosure will be described in
further detail with reference to the following examples and
comparative examples.
[0056] Table 1 shows the composition, saturation magnetic flux
density (T), resistivity (.mu..OMEGA.cm), and amorphous formability
of each of soft magnetic alloys according to examples. Table 2
shows the composition, saturation magnetic flux density (T),
resistivity (.mu..OMEGA.cm), and amorphous formability of each of
soft magnetic alloys according to comparative examples. FIG. 6 is a
thermal analysis graph of a soft magnetic alloy prepared according
to Example 1. FIG. 7 illustrates X-ray diffraction (XRD) pattern
analysis of the soft magnetic alloy of Example 1. FIG. 8
illustrates saturation magnetic flux density of the soft magnetic
alloy of Example 1.
[0057] Each of the soft magnetic alloys according to the examples
and the comparative examples was prepared by melting metal powder
according to each composition in a molten metal, producing alloy
powder by cooling the resulting molten solution by spraying gas or
water, and then heat-treating the alloy powder at 200.degree. C. to
1,000.degree. C.
[0058] The saturation magnetic flux density (T) of each of the soft
magnetic alloys according to the examples and the comparative
examples was measured using a vibrating sample magnetometer (VSM),
and the resistivity (.mu..OMEGA.cm) of each soft magnetic alloy was
measured using a point probe. In addition, the amorphous
formability of each of the soft magnetic alloys of the examples and
the comparative examples was determined according to whether it is
possible to form a ribbon or a cylindrical rod, and for this,
thermal analysis and XRD pattern analysis were performed.
TABLE-US-00001 TABLE 1 Saturation Experi- magnetic ment Composition
flux density Resistivity Amorphous No. (at. %) (emu/g) (.mu..OMEGA.
cm) formability Example 1 Fe.sub.80Si.sub.2P.sub.8C.sub.6B.sub.4
195 160 Passed (ribbon and 1 mm-) diameter cylinder Example 2
Fe.sub.78Si.sub.8C.sub.6B.sub.8 200 189 Passed (ribbon) Example 3
Fe.sub.82P.sub.8C.sub.6B.sub.4 185 168 Passed (ribbon) Example 4
Fe.sub.80P.sub.8C.sub.6B.sub.4Al.sub.2 175 172 Passed (ribbon and 1
mm- diameter cylinder) Example 5
Fe.sub.80P.sub.8C.sub.6B.sub.4Co.sub.2 179 165 Passed (ribbon and 1
mm- diameter cylinder)
TABLE-US-00002 TABLE 2 Saturation Composition magnetic flux
Resistivity Experiment No. (at. %) density (emu/g) (.mu..OMEGA. cm)
Amorphous formability Comparative Fe.sub.78Si.sub.13B.sub.9 165 120
Passed (ribbon) Example 1 Comparative
Fe.sub.76Si.sub.9B.sub.10P.sub.5 158 -- Passed (ribbon and 1.5
Example 2 mm-diameter cylinder) Comparative Fe.sub.93.5 wt
%Si.sub.6.5 wt % 162 82 Failed (amorphous Example 3 formation is
impossible)
[0059] Referring to Tables 1 and 2 and FIGS. 6 to 8, it can be
confirmed that the soft magnetic alloys of Examples 1 to 5 having
the composition of Formula 1 have a saturation magnetic flux
density of 170 emu/g or more and excellent amorphous formability,
whereas the soft magnetic alloys of Comparative Examples 1 to 3
that are outside the above numerical range exhibit at least one of
poor saturation magnetic flux density and poor amorphous
formability. In particular, it can be confirmed that the case of
Example 1 including all of Fe, Si, P, C, and B and having a
composition that satisfies the conditions of Formula 1 exhibits
high saturation magnetic flux density and excellent amorphous
formability.
[0060] In addition, in the cases of Examples 1, 3, 4, and 5, since
the content of Fe exceeds 78 at %, a total content of the remaining
elements that contribute to amorphous formation (e.g., Si, P, C, B,
Al, and Co) is less than 22 at %. Generally, as the content of Fe
that contributes to saturation magnetic flux density is increased,
the contents of the remaining elements that contribute to amorphous
formability are decreased, and thus the saturation magnetic flux
density and the amorphous formability have a trade-off
relationship. However, according to the compositions of embodiments
of the present invention, high saturation magnetic flux density may
be obtained and amorphous formability may be maintained.
[0061] The soft magnetic alloy according to an embodiment of the
present invention may be applied to various sheets for shielding an
electromagnetic field. For example, the soft magnetic alloy
according to an embodiment of the present invention may be applied
to a soft magnetic sheet of a wireless power receiver for wireless
charging, a shielding sheet for a radio frequency identification
(RFID) antenna, and the like.
[0062] In addition, the soft magnetic alloy according to an
embodiment of the present invention may be applied to a soft
magnetic core for a transformer, a soft magnetic core for a motor,
a magnetic core for an inductor, or a soft magnetic core for a
wireless power transmitter for wireless charging. For example, the
soft magnetic alloy according to an embodiment of the present
invention may be applied to a magnetic core on which a coil is
wound or a magnetic core in which a wound coil is accommodated.
[0063] Furthermore, the soft magnetic alloy according to an
embodiment of the present invention may be variously applied to
environmentally-friendly automobiles, high-performance electronic
devices, and the like.
[0064] While the present invention has been described in detail
with reference to exemplary embodiments, it will be understood by
those of ordinary skill in the art that various changes and
modifications may be made therein without departing from the spirit
and scope of the present invention as defined in the appended
claims.
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